Police raided the Hong Kong office of online car-hire giant Uber and arrested five drivers on Tuesday in a crackdown on unlicensed transport services.

The operation, codenamed Cellbreaker, comes amid increased pressure from the powerful taxi lobby, which has criticised the government for failing to curb cab-hailing apps. It is the latest in a series of conflicts internationally between fast-growing Uber and taxi drivers and cab owners fearful they will lose their business.

Undercover officers on Tuesday posed as customers and hired cars via the Uber app in Tsim Sha Tsui, Kwun Tong and Sha Tin. The drivers, aged between 28 and 65, were arrested at their destination in Kowloon City. The officers paid fares of between HK$70 and HK$170 by credit card.

The five were being detained for allegedly using a car for hire without a permit and driving without suitable insurance. They were later released on police bail. Five vehicles, including three seven-seater cars, were impounded.

“We are confident that there is sufficient evidence to prosecute the drivers,” said Chief Inspector Bruce Hung Hin-kau of the police traffic unit. “We will seek legal guidance … if there are any problems.”

Officers later raided the office of Uber in Cheung Sha Wan Road and took three staff away for inquiries, a police source said. The three were later arrested. A further raid took place at the company’s offices in Sheung Wan later in the day, where computers and documents were seized.

Hung said the investigation was continuing and appealed to the public not to use such services.